Black?? algae

[momo]

I seem to have this black algae crawling over my Live rocks. Any suggestions on what it is and can I get rid of it. Water tested Everthing fine.

 

[iyachtuxivm]

Cyano. Search it here and you will find many many threads about it. I had it I used chemiclean to get rid of it after many failed other attempts. But only use a chemical as a last resort you may have better luck.

 

[pezenfuego]

Pics would be nice for confirmation. Cyano isn't really "black." I'm not saying that you're wrong, I'm just saying that without pictures, it is hard to tell. It could be dino